Problem: Simplify the expression. $(-7k^{3}-5k^{2})(6k^{2}-7k)$
First use the distributive property. $ - 7 k^3 (6 k^2) - 7 k^3 (-7 k) - 5 k^2 (6 k^2) - 5 k^2 (-7 k) $ Simplify. $ - 42k^{5} + 49k^{4} - 30k^{4} + 35k^{3} $ $-42k^{5}+19k^{4}+35k^{3}$ Identify like terms. $ {- 42k^{5}} {+ 49k^{4}} {- 30k^{4}} {+ 35k^{3}} $ Add the coefficients. $ { -42k^{5}} {+ 19k^{4}} {+ 35k^{3}} $